What are the Dog Days of Summer? A time when we must lavish our dogs with treats, hugs and daily hikes?
My dogs are pretty much used to that kind of treatment already, but I’m sure they wouldn’t mind a bit more attention. Sadly, for them, the dog days aren’t about dogs at all, but rather about the brightest star in the sky, Sirius. Known as the “dog star,” it is part of the constellation Canis Majoris. The rising of this star at sunrise coincides with the hot, humid days associated with July and August, giving them the name “dog days.”
Dog-day cicada
There is an insect that thrives during this time of high temperatures and peak humidity. So much so, that it bears the name dog-day cicada (Neotibicen canicularis). For many of us, summer isn’t summer without the incessant songs from these insects throughout the day.
Starting low and slow, a buzzing noise can be heard from the trees. Rapidly, the winy drone picks up speed and volume. Sounding much like the high-pitched buzz from an electric saw, it finally begins to taper off before becoming silent. The whole performance lasts around 15 seconds and can reach a whopping 100 decibels. It is impressive, to say the least.
In North America, there are around 170 species of cicadas. In Ohio, there are 12. These are often erroneously referred to as “locusts.” A locust is actually a type of grasshopper known for traveling in large swarms and devouring all the vegetation in their path.
Although locusts are not even found in the United States, the association between the two species dates back to colonial times. Large emergences of periodical cicadas, with their deafening vocalizations, had the colonists convinced that they were experiencing locust plagues. Thus, the mistake of interchanging the two names began.
The dog-day cicada, also known as the annual cicada, is impressive, to say the least. Measuring nearly 2 inches in length, by ½ inch in width, the adult insect appears fearsome but is completely harmless. Sporting a green, brown and black, bullet-shaped body, it has four semi-transparent wings with green veins that are held tent-like above its back. A pair of short antennae and prominent bulging compound eyes set far apart complete its portrait.
Cicada songs
When we hear the characteristic “singing,” it is coming from the male, as he sits on the side of a tree hoping to attract a mate. Only the males call, and their musical instrument is quite extraordinary. Cicadas possess an organ unique among insects.
The “tymbal” is comprised of a pair of ridged membranes near the tip of the abdomen. Contractions of the muscle attached to the membranes cause them to bend and click. The frequencies of these contractions range from 120 to 480 times per second, which causes a nearly continuous call that humans are able to perceive. A nearly empty abdomen helps to amplify the sound.
Once mating has occurred, the female uses her ovipositor, a structure at the tip of her abdomen, to cut small slits into branches of trees and shrubs and deposit clusters of eggs. After about 6 weeks, these eggs hatch into tiny nymphs that drop to the ground and immediately burrow several feet into the soil. Here, they seek out tree roots and feed on sap.
During their 2- to 5-year tenure underground, the nymphs grow and molt several times. Once fully developed, they prepare for their grand entrance into the world. Under the cover of darkness, they use their strong front legs to burrow out of the soil, leaving a round, ½” hold behind.
Once on a stable vertical surface, they split their skin allowing their adult body to emerge. Much like that of a butterfly or moth, their wings are tiny at first but slowly expand over the course of several hours. By daybreak, their wings have hardened, and they take flight, leaving behind an empty shell. It is this intriguing exoskeleton that we come across so often during this time of year. Adult cicadas live for 5 to 6 weeks, sucking juices from tender twigs and doing little if no damage.
Periodical cicada
Our area is also home to the longest-lived insect in North America. The periodical cicada (Magicidada spp.) puts on a show of amazing proportion as regional broods emerge en masse every 13 to 17 years. Slightly smaller than our annual cicada species, the periodical cicadas have red eyes and orange wing veins. Known here as brood V, the most recent emergence was in 2016.
As an insect lover, I enjoyed every second of the overwhelming spectacle and look forward to it happening again in 2033. Sadly, as more and more developments eliminate the trees whose roots these nymphs depend upon for so many years, the broods become smaller and smaller, sometimes completely disappearing from existence in some areas.
Many may ask the question, “What good are cicadas?” For one thing, mass emergences of periodical cicadas help to aerate the soil. They also put nitrogen back into the soil after they perish. When eggs are laid, it forms a weak spot which eventually causes the branch to break off. This natural pruning contributes to a stronger tree crown.
Finally, cicadas provide a hefty meal for so many animals. The cicada-killer wasp, the largest in Ohio, wrestles cicadas and stashes them as a food source for their offspring. Birds, reptiles, amphibians, fish, raccoons and opossums, to mention a few, all enjoy dining on the nutrient-rich insects. And, that’s right, even our dogs love ‘em too!
According to folklore, cicadas can predict the weather. It is said that when you hear the initial dog-day cicada sing, the first frost of autumn is just 6 weeks away.
The sweltering dog days of August certainly don’t have me anxious to grant my canines additional hikes. Rather, I would much prefer to rest with them in the shade of a big tree while the gentle buzz of the dog-day cicada summoning a mate, lulls me to sleep.
